Metrics used to evaluate obstetric ultrasound skills on simulators: A systematic review

International audienceObstetric ultrasound simulators are now used for training and evaluating OB/GYN students but there is a lack of literature about evaluation metrics in this setting. In this literature review, we searched MEDLINE and the COCHRANE database using the keywords: (Obstetric OR Fetal) AND (Sonography OR Ultrasound) AND Simulation. Of a total of 263 studies screened, we selected nine articles from the title and the abstract in PubMed, in the past 5 years. Two more article were added from bibliographies. A total of 11 articles were therefore included. from which nine articles were selected from the title and the abstract in PubMed. Two more articles were added from the bibliographies For each study, data about the type of simulation, and the metrics (qualitative or quantitative) used for assessment were collected. The selection of studies shows that evaluation criteria for ultrasound training were qualitative metrics (binary success/fail exercise ; dexterity quoted by an external observer ; Objective Structured Assessment of Ultrasound Skills (OSAUS) Score ; quality of images according to Salomon’s score) or quantitative criteria (Accuracy of Biometry - Simulator generated metrics). Most studies used a combination of both. To date, simulator metrics used to discriminate ultrasound skills are performance score quoted by external observers and image quality scoring. Whether probe trajectory metrics can be used to discriminate skills is unknown

Validation of virtual reality arthroscopy simulator relevance in characterising experienced surgeons

International audienceBACKGROUND: Virtual reality (VR) simulation is particularly suitable for learning arthroscopy skills. Despite significant research, one drawback often outlined is the difficulty in distinguishing performance levels (Construct Validity) in experienced surgeons. Therefore, it seems adequate to search new methods of performance measurements using probe trajectories instead of commonly used metrics. HYPOTHESIS: It was hypothesized that a larger experience in surgical shoulder arthroscopy would be correlated with better performance on a VR shoulder arthroscopy simulator and that experienced operators would share similar probe trajectories. MATERIALS and METHODS: After answering to standardized questionnaires, 104 trajectories from 52 surgeons divided into 2 cohorts (26 intermediates and 26 experts) were recorded on a shoulder arthroscopy simulator. The procedure analysed was the "loose body removal" in a right shoulder joint. 10 metrics were computed on the trajectories including procedure duration, overall path length, economy of motion and smoothness. Additionally, Dynamic Time Warping (DTW) was computed on the trajectories for unsupervised hierarchical clustering of the surgeons. RESULTS: Experts were significantly faster (Median 70.9s Interquartile range [56.4-86.3] vs. 116.1s [82.8-154.2], p<0.01), more fluid (4.6.10(5)mm.s(-3) [3.1.10(5)-7.2.10(5)] vs. 1.5.10(6)mm.s(-3) [2.6.10(6)-3.5.10(6)], p=0.05), and economical in their motion (19.3mm² [9.1-25.9] vs. 33.8mm² [14.8-50.5], p<0.01), but there was no significant difference in performance for path length (671.4mm [503.8-846.1] vs 694.6mm [467.0-1090.1], p=0.62). The DTW clustering differentiates two expertise related groups of trajectories with performance similarities, respectively including 48 expert trajectories for the first group and 52 intermediates and 4 expert trajectories for the second group (Sensitivity of 92%, Specificity of 100%). Hierarchical clustering with DTW significantly identified expert operators from intermediate operators and found trajectory similarities among 24/26 experts. CONCLUSION: This study demonstrated the Construct Validity of the VR shoulder arthroscopy simulator within groups of experienced surgeons. With new types of metrics simply based on the simulator’s raw trajectories, it was possible to significantly distinguish levels of expertise. We demonstrated that clustering analysis with Dynamic Time Warping was able to reliably discriminate between expert operators and intermediate operators. Clinical Relevance The results have implications for the future of arthroscopic surgical training or post-graduate accreditation programs using virtual reality simulation. LEVEL OF EVIDENCE: III; prospective comparative study

High Risk of Anal and Rectal Cancer in Patients With Anal and/or Perianal Crohn’s Disease

International audienceBackground & AimsLittle is known about the magnitude of the risk of anal and rectal cancer in patients with anal and/or perineal Crohn’s disease. We aimed to assess the risk of anal and rectal cancer in patients with Crohn’s perianal disease followed up in the Cancers Et Surrisque Associé aux Maladies Inflammatoires Intestinales En France (CESAME) cohort.MethodsWe collected data from 19,486 patients with inflammatory bowel disease (IBD) enrolled in the observational CESAME study in France, from May 2004 through June 2005; 14.9% of participants had past or current anal and/or perianal Crohn’s disease. Subjects were followed up for a median time of 35 months (interquartile range, 29–40 mo). To identify risk factors for anal cancer in the total CESAME population, we performed a case-control study in which participants were matched for age and sex.ResultsAmong the total IBD population, 8 patients developed anal cancer and 14 patients developed rectal cancer. In the subgroup of 2911 patients with past or current anal and/or perianal Crohn’s lesions at cohort entry, 2 developed anal squamous-cell carcinoma, 3 developed perianal fistula–related adenocarcinoma, and 6 developed rectal cancer. The corresponding incidence rates were 0.26 per 1000 patient-years for anal squamous-cell carcinoma, 0.38 per 1000 patient-years for perianal fistula–related adenocarcinoma, and 0.77 per 1000 patient-years for rectal cancer. Among the 16,575 patients with ulcerative colitis or Crohn’s disease without anal or perianal lesions, the incidence rate of anal cancer was 0.08 per 1000 patient-years and of rectal cancer was 0.21 per 1000 patient-years. Among factors tested by univariate conditional regression (IBD subtype, disease duration, exposure to immune-suppressive therapy, presence of past or current anal and/or perianal lesions), the presence of past or current anal and/or perianal lesions at cohort entry was the only factor significantly associated with development of anal cancer (odds ratio, 11.2; 95% CI, 1.18-551.51; P = .03).ConclusionsIn an analysis of data from the CESAME cohort in France, patients with anal and/or perianal Crohn’s disease have a high risk of anal cancer, including perianal fistula–related cancer, and a high risk of rectal cancer